The present invention relates to gas turbine engines. In particular, the invention relates to a centrifugal compressor impeller for use in gas turbine engines.
Gas turbine engines generally comprise a compressor and a turbine wheel. Smaller gas turbines often employ a centrifugal compressor, due to its inherent space efficiency. The primary component of a centrifugal compressor is a compressor impeller. The compressor impeller compresses incoming air which is directed through a diffuser to a combustion chamber, mixed with fuel and ignited. The turbine wheel is propelled by rapidly expanding gases resulting from the combustion of the fuel and the compressed incoming air. The compressor impeller is linked to, and powered by, the turbine wheel.
Overall gas turbine engine cycle efficiency is determined in part by a compression ratio (air pressure exiting the compressor divided by the air pressure entering the compressor). The higher the compression ratio, the higher the gas turbine engine cycle efficiency. The compression ratio is a function of the efficiency of the compressor and compressor impeller. The greater the compression ratio for a given flow rate and work factor, the more efficient the compressor impeller.